Это даст ожидаемый результат
из комбинаций импорта itertools
original_set = (0,1,2,3,4,5,6,7,8)
final_set = [list(pair) for pair in combinations(l, 3)]
Out[6]:
[[0, 1, 2],
[0, 1, 3],
[0, 1, 4],
[0, 1, 5],
[0, 1, 6],
[0, 1, 7],
[0, 1, 8],
[0, 2, 3],
[0, 2, 4],
[0, 2, 5],
[0, 2, 6],
[0, 2, 7],
[0, 2, 8],
[0, 3, 4],
[0, 3, 5],
[0, 3, 6],
[0, 3, 7],
[0, 3, 8],
[0, 4, 5],
[0, 4, 6],
[0, 4, 7],
[0, 4, 8],
[0, 5, 6],
[0, 5, 7],
[0, 5, 8],
[0, 6, 7],
[0, 6, 8],
[0, 7, 8],
[1, 2, 3],
[1, 2, 4],
[1, 2, 5],
[1, 2, 6],
[1, 2, 7],
[1, 2, 8],
[1, 3, 4],
[1, 3, 5],
[1, 3, 6],
[1, 3, 7],
[1, 3, 8],
[1, 4, 5],
[1, 4, 6],
[1, 4, 7],
[1, 4, 8],
[1, 5, 6],
[1, 5, 7],
[1, 5, 8],
[1, 6, 7],
[1, 6, 8],
[1, 7, 8],
[2, 3, 4],
[2, 3, 5],
[2, 3, 6],
[2, 3, 7],
[2, 3, 8],
[2, 4, 5],
[2, 4, 6],
[2, 4, 7],
[2, 4, 8],
[2, 5, 6],
[2, 5, 7],
[2, 5, 8],
[2, 6, 7],
[2, 6, 8],
[2, 7, 8],
[3, 4, 5],
[3, 4, 6],
[3, 4, 7],
[3, 4, 8],
[3, 5, 6],
[3, 5, 7],
[3, 5, 8],
[3, 6, 7],
[3, 6, 8],
[3, 7, 8],
[4, 5, 6],
[4, 5, 7],
[4, 5, 8],
[4, 6, 7],
[4, 6, 8],
[4, 7, 8],
[5, 6, 7],
[5, 6, 8],
[5, 7, 8],
[6, 7, 8]]